As the starting fullback for the Chargers, and an allegedly undersized one at that, Jacob Hester has to play by two solid principles:

Stay low. Don’t get hurt.

The first part comes natural to Hester, not the tallest player in the National Football League at 5-foot-9, but also also taught by his father (and coach) since Pee-Wee’s to always get lower than the guy trying to tackle him. The part about not getting hurt, well, that’s also become quite a necessity.

“If you’re the fullback,” said Hester, “you can’t get hurt when your backup fullback is a starting tailback who’s running for 100 yards a game.”

That would be Mike Tolbert, who began the season as a No. 2 tailback, but since has scored nine touchdowns and reeled off three 100-yard rushing games, including each of the last two wins. Returning from Indianapolis with a right hand that was injured and heavily taped, however, Tolbert was withheld from practice Wednesday.

In the event that Tolbert can’t go, first-round draft choice Ryan Mathews may be returning from injury at the right time. Hester and Tolbert have developed a close relationship since coming to the Chargers under vastly different circumstances in 2008, but whoever has the ball, Hester’s got their front.

“I really like Jacob Hester as a fullback,” said NBC analyst Cris Collinsworth during the Chargers win at Indianapolis. “He is the most un-fullback-looking guy that you will see, but he has a way of digging guys out.”

Un-fullback-looking. Imperfectly perfect.

Actually, Hester’s OK-sized at 240 pounds, 10 pounds heavier than when he was more like a backup tailback playing fullback last year. Only this calendar year, with the Chargers’ taking Mathews so high in the draft, did Hester know that his future in the NFL was as a fullback. He began lifting _ and eating _ accordingly.

“If you think about it, a lot of linebackers are only 245,” said Hester. “I just don’t look that big.”

You know who does, though, don’t you? Tolbert.

“We joke all the time about it,” said Hester, referring to the fellow 5-9 back who’s considerably thicker. “We might be the only combo where the running back weighs more than the fullback, but it’s been working. Mike’s idol was The Bus, Jerome Bettis. He said that might’ve been the only other case where the fullback was smaller than the tailback.”

They’ve become quite the pair. In the backfield. On special teams. Anywhere, really.

Hester came to the Chargers as a third-round draft choice from LSU who was the tailback on a national-championship team. Tolbert was an undrafted free agent from Coastal Carolina. Thrust together, but vying with each other for essentially the same job, they somehow became fast friends.

“It helps us a ton in games,” said Hester. “He trusts me as much as I trust him. Between a fullback and a tailback, that’s huge. I’m not saying I don’t have that with Ryan and Darren (Sproles). It’s just a little different with me and Mike.

“We came in together and shared the position. We’ve never got mad at who was playing. It’s always been a really healthy relationship. When we were competing for the same job, we were helping each other out.”

They’re fortunate to be playing on one of the few teams to regularly use a two-back set, and with Hester’s skill-position abilities, the Chargers have utilized him as a receiver for 21 receptions and a touchdown. Moreover, because he’s been both, he knows all the plays from the fullback and tailback perspectives.

Clearly, though, he’s made that mental transition from running to blocking back. Saying he used to think he had to “knock out guys” with his blocks, Hester’s come to realize that it’s more efficient for someone his size to use leverage and angles to clear a path, something that really hit home with him in a conversation he had with veteran center Nick Hardwick.

One of Hardwick’s former Chargers teammates, meanwhile, has been watching with a personal interest in what Hester’s doing.

“Fullback’s an art, but it’s a train wreck,” said Lorenzo Neal, now retired, but still considered the NFL’s gold standard for the position. “You’re taking the brunt of linebackers coming downhill. (Hester)’s been impressive. I think he’s found his niche.

“There’s more than one way to get people out of the way. Me, I’d hit ‘em up high. I'd run a straight line and I went until I heard glass. Hester cuts people down, taking out their legs. What he brings to the position is good, creating some uncertainty in the defensive guys, and he and the big boy (Tolbert) seem to work well together .”